Best type of Sub to consider?

Great idea, Kenny. Danny comes at subs from a perfectionist audiophile, music-centric point of view. Brian is an unusual sub designer in that his priority is also music reproduction, unlike the home-theater orientation of most sub designers. But GR Research subs are used in music-only systems, Rythmik’s as much in home theater systems as in music ones.

The servo-feedback Rythmiks have a "stop-on-a-dime" cleanness to them that makes ordinary subs sound like they are filling in the empty spaces with "noise"---the drivers don’t stop and come back to rest when the notes stop. Rythmiks have what Peter Moncrieff of IAR calls "inter-transient silence". No matter which Rythmik/GR Research sub model you choose, you will get that sound. When you talk to Danny, tell him Eric sent ya!

Kenny-

look and listen no further than REL.

I contacted Danny from GR Research and he was a wealth of information. I wanted to know how an open baffle design would be an advantage in my room's layout. He responded, open baffle woofers don't load the room like a sealed or ported sub. So the OB woofers greatly minimize room boom.

Apparently, the OB Subs should not get placed close to a wall, but rather at least three feet from my back wall, which makes them a great setup if placed to the sides of my speakers.

Kenny

What’d I tell ya Kenny! Being a dipole, the OB sub has a null to each side, creating two benefits: First, it loads the depth dimension of the room, but not the width, exciting the longer, further apart nodes rather than the shorter, closer together one’s. Already you have gotten rid of one source of room boom. Second, the side nulls allow the OB sub to be placed right next to your main speakers should you wish to, or right up against a side wall if you have a narrow room. True, it has to be away from the wall behind it (like any dipole), but most speakers sound better there too. And here’s a bonus: the sub can be laid on it’s side and used as a base for a pair Quad ESL’s or other short speakers. That’s just what the Gradient OB/Dipole Sub made for the Quad 63 was. The difference here is that you have the much higher quality GR Research 12’ woofer, and the Rythmik Direct Servo-Feedback system controlling the dual woofers. As I said, a very special sub, one few people have heard but when do are blown away by.

By the way, you can see a pic of the OB/Dipole Sub in the current thread about Virtual Systems.